Naarmate het variabele tarief hoger wordt, wordt het termijnbedrag hoger.

Naarmate means something like as, in proportion as, or the more ... the more ....

It introduces a relationship where one thing changes together with another:

• Naarmate het variabele tarief hoger wordt, ... = As the variable rate becomes higher, ...

A very natural English equivalent for the whole sentence is:

• The higher the variable rate gets, the higher the installment amount gets.

So naarmate is often used when two developments happen alongside each other.

Because there are two separate clauses, and each clause has its own verb:

1. Naarmate het variabele tarief hoger wordt
2. wordt het termijnbedrag hoger

Both clauses describe something becoming higher, so both use worden.

• het variabele tarief hoger wordt = the variable rate becomes higher
• het termijnbedrag hoger wordt = the installment amount becomes higher

So the repetition is completely normal.

This is because of Dutch word order.

In the subordinate clause introduced by naarmate, the conjugated verb usually goes toward the end:

• Naarmate het variabele tarief hoger wordt

In the main clause, Dutch normally uses verb-second word order, meaning the finite verb comes in the second position:

• wordt het termijnbedrag hoger

So:

• subordinate clause: verb near the end
• main clause: finite verb in second position

That is why you get:

• Naarmate ..., wordt ...

Because the first clause has already taken the first position in the sentence.

Dutch main clauses usually follow the V2 rule: the finite verb must come second. If a subordinate clause comes first, the verb of the main clause comes immediately after it.

So:

• Naarmate het variabele tarief hoger wordt, wordt het termijnbedrag hoger.

Structure:

1. first position: Naarmate het variabele tarief hoger wordt
2. second position: wordt
3. then the subject: het termijnbedrag

This is very common in Dutch:

• Als het regent, blijf ik thuis.
• Wanneer hij komt, beginnen we.

Same pattern.

Hoger is the comparative form of hoog:

• hoog = high
• hoger = higher

The sentence compares changing levels, so Dutch uses the comparative:

• het tarief wordt hoger = the rate gets higher
• het termijnbedrag wordt hoger = the installment amount gets higher

If you said hoog, it would just describe a fixed state:

• Het tarief is hoog = The rate is high

But here the idea is change, so hoger is the right form.

Because worden means to become / to get, while zijn means to be.

This sentence is about a change over time:

• het variabele tarief hoger wordt = the variable rate becomes higher
• het termijnbedrag hoger wordt = the installment amount becomes higher

If you used zijn, you would describe a state, not a change:

• Het tarief is hoog = the rate is high
• Het tarief wordt hoog/hoger = the rate becomes high/higher

So worden is the natural choice here.

Termijnbedrag is a compound noun:

• termijn = term / installment period
• bedrag = amount

Together, termijnbedrag means the amount you pay per term or installment, often something like a monthly payment amount.

In financial contexts, it can refer to the amount due each billing period.

They are related, but they are not the same:

• tarief = rate, tariff, charge level
• bedrag = amount, sum of money

So in this sentence:

• het variabele tarief is the variable rate
• het termijnbedrag is the actual installment amount

In other words, the rate goes up, so the amount you must pay each term goes up too.

Because tarief is a het-word.

In Dutch, every noun has grammatical gender/common article:

• de
• het

You simply have to learn which article belongs to each noun.

Here:

• het tarief
• het bedrag
• therefore also het variabele tarief
• and het termijnbedrag

Because adjectives usually take an -e ending when they come before a noun.

So:

• een variabel tarief can occur in some contexts, because after een with a neuter singular noun and no definite form, the adjective may stay without -e
• but het variabele tarief takes -e because it is definite

Here the noun phrase is definite:

• het variabele tarief

So the adjective is:

• variabele

This is a very common Dutch pattern.

Yes, it is in the present tense:

• wordt
• wordt

Dutch often uses the present tense for general truths, rules, or patterns. This sentence is not necessarily about one single moment right now; it expresses a general relationship:

• when one thing rises, the other rises too

That is exactly the kind of thing Dutch commonly states in the present tense.

Yes. Dutch can express a similar idea with a structure like hoe ..., hoe ..., though naarmate is very natural in formal or explanatory language.

A similar version would be:

• Hoe hoger het variabele tarief wordt, hoe hoger het termijnbedrag wordt.

That means almost the same thing:

• The higher the variable rate gets, the higher the installment amount gets.

So naarmate and hoe ..., hoe ... can overlap in meaning here, though the phrasing is slightly different.

Yes, the comma is standard here because the sentence begins with a subordinate clause:

• Naarmate het variabele tarief hoger wordt, wordt het termijnbedrag hoger.

Dutch normally places a comma between a fronted subordinate clause and the main clause. That makes the structure clearer and easier to read.

Yes, that is an excellent way to understand it.

A useful pattern to remember is:

• Naarmate X hoger/lager wordt, wordt Y hoger/lager.

Examples:

• Naarmate de temperatuur stijgt, wordt het warmer in huis.
• Naarmate de kosten hoger worden, wordt de winst lager.

So your sentence fits a very common Dutch pattern for linked change.